<html>
  <head>
    <style>
      body {
        margin: 0;
      }
      #container {
        display: flex;
        flex-direction: column;
        border: 10px solid lime;
        width: 80px;
        height: 80px;
        background-color: red;
      }
      #item {
        background-color: lime;
        min-height: 0;
        width: 80px;
        height: auto;
        line-height: 80px;
      }
    </style>
  </head>
  <body>
    <div id="container">
      <div id="item">&nbsp;</div>
    </div>
  </body>
</html>
